Followup: FTL neutrinos explained? Not so fast, folks.

By Phil Plait | October 15, 2011 3:20 pm

If you haven’t heard about the experiment that apparently showed that subatomic particles called neutrinos might move faster than light (what we in the know call FTL, to make us look cooler), then I assume this is your first time on the internet. If that’s the case, then you can read my writeup on what happened.

Basically, neutrinos move very very fast, almost at the speed of light. Some scientists created neutrinos at CERN in Geneva, and then measured how long it took them to reach a detector called OPERA, located in Italy. When they did the math, it looked like the neutrinos actually got there by traveling a hair faster than the speed of light! 60 nanoseconds faster, to be accurate.

Was relativity doomed?

Nope. In fact, relativity may very well be what saves the day here.

First, most scientists were skeptical. Even the people running the experiment were skeptical, and were basically asking everyone else for help. They figured they might have made a mistake as well, and couldn’t figure out what had happened. Relativity is an extremely well-tested theory, and doesn’t (easily) allow for FTL. Despite some headlines screaming that Einstein might be wrong, most everyone figured the problem lay elsewhere.

Most everyone zeroed in on the timing of the experiment, which has to be extremely accurate. The entire flight time of a neutrino from Switzerland to Italy is only about 2.4 milliseconds, and the measurement accuracy needs to be to only a few nanoseconds — mind you, a nanosecond is a billionth of a second!

The scientists used a very sophisticated GPS setup to determine the timing, so that has been the focus of a lot of scrutiny as well. And a new paper just posted on the Physics Preprint Archive may have the answer… and it uses relativity.

Basically, what Einstein found is that the speed of light is the same for all observers. If I’m moving at 0.9 times the speed of light toward you and turn on my flashlight, I see those photons moving away from me at the speed of light. The thing is, you see those photons moving toward you at the speed of light! This goes against common sense, which tells us that velocities add together; if I throw a baseball out car window, the velocity of the ball add to that of the car.

But light doesn’t behave that way. And this changes a lot of things, including how two objects moving relative to each other measure distance, and even how they measure time. I might measure a meter stick in my hand as being (duh) one meter long, but an observer moving past me at a significant fraction of the speed of light would see it being shorter. It’s just a consequence of the Universe making sure we all see the same speed of light.

And that’s where neutrinos come in. In this new paper, author Ronald A.J. van Elburg lays out his case. The timing was measured using a GPS satellite orbiting the Earth, and moving relative to CERN and OPERA. That means the distance traveled by the neutrinos would be less as measured by the GPS sat as it would be from the ground, and therefore wouldn’t take as long to cover it. Doing the detailed math, van Elburg calculates how much faster the neutrinos would be expected to arrive accounting for the satellite’s motion, and he gets… 64 nanoseconds. That’s almost exactly the discrepancy measured by the original experimenters.

Case closed!

Well, maybe. As I recall from the foofooraw that unfolded after the initial announcement, the original experimenters said they accounted for all relativistic effects. The paper they published, however, didn’t include the details of how they did this, so it’s not clear what they included and what they might have left out. It’s possible van Elburg might be right, but I expect we haven’t seen the end of this. After all, not long after the announcement, a physicist asked if they had accounted for gravitational time dilation — like relative velocity, gravity can also affect the flow of time, throwing off the measurement — and the experimenters said they had.

I had thought of something like this as well. CERN and OPERA are at different latitudes, and since the Earth rotates, they are moving around the Earth’s axis at different speeds. Could that be it? I did the math, and the answer is no. Too bad; it would’ve been fun to be the person to have figured this out!

The bottom line here is that this experiment is still very interesting. I don’t think we know exactly what’s going on here yet — my bet is still on the statistics, since they didn’t measure the speeds of individual neutrinos, but clouds of them, making the exact timing much harder — but it’s hard to say. Like most other scientists, I think somewhere down the line here a mistake was made, and the neutrinos, like everything else we know of made of matter, travel slower than light. But if we’re wrong, then we get new physics, which is great! And if we’re right and figure out how, it means that future experiments will benefit from this. Win/win.

Either way, my bet is that we’re not done here. This new result is interesting and may very well be right, and be the dampening field that bursts the neutrino FTL warp bubble. But I’ll wait for the reaction from the original experimenters to see what they say. If we’ve learned one thing from all this, it’s that it’s best not to jump to conclusions.


Related posts:

Faster-than-light travel discovered? Slow down, folks
A (very) smart kid and a solid theory
Wall Street Journal: neutrinos show climate change isn’t real
Followup on the WSJ climate denial OpEd

CATEGORIZED UNDER: Cool stuff, Debunking, Science, Skepticism

Comments (126)

  1. Psst! There’s a ‘than’ that should be a ‘then’ in the first sentence.

  2. Tim G

    Relativity isn’t going to go away. It can only be expanded or refined.

  3. Sorry if you’ve mentioned this before, but what about failure to account for the curvature of the earth?

  4. edwardv

    Could the supposed error have been in the other direction and the measured speed slightly slower than the actual speed? How would an error like that have been suspected or identified?

  5. Sindragosa

    I’m confused. Don’t GPS satellites already adjust for SR and GR? Don’t we always use that example when we want to show how robust SR and GR are?

  6. You know what I think is the best thing about all this? Whatever the outcome, it’s got a lot of people talking about relativity, and I’m sure plenty of people have learned a bit about it too. We need more public discussions on scientific topics like this, especially when they can actually engage the general public and get them thinking. Whatever the solution turns out to be, everybody wins.

  7. Satan Claws

    Naturally, the proposed explanations abound. This one doesn’t use fancy phenomena to justify the time shift:
    http://arxiv.org/abs/1110.0239

  8. DrFlimmer

    That might cool down some folks here and there. I know of a group of physicists who calculated some weired stuff with neutrinos taking a short-cut through an assumed fifth dimension. And that short-cut could have led to the neutrinos being clocked as FTL (I want to sound cool, as well ;) ). I was told (their institute is located not far from mine…) that they were running around like hell, perhaps already throwing parties for next years Nobel Prize… and probably I am just exaggerating. ;)

    Still, a “reasonable” solution (wrong measurements) is better than such a made-up stuff. But that’s just my opinion for the moment.

  9. Khan

    - The experiement was done 15000 times, over 3 yrs and speed measured to 6-sigma. If this 32 nanosecond error in each direction is accurately calculated and accounts for the difference that OPERA derived then consequenty, the same level of accuracy could be applied to the velocity these satelites were orbiting, the constant speed they orbited varied and the thier distance from earth should be also taken into account. This all effects measured time-space measured by the orbitor, especially when we consider the 6-sigma. The net effect would have altering neutrino measurments, over the course of 3 years, which was not the case and especially over 64 nanoseconds.

  10. Iain

    I assume Dr Flimmer is talking about M brane/superstring/multiple dimensional theorists.
    It would be nice if some positive evidence came their way.

  11. Grand Lunar

    I wonder if they really did account for ALL relativistic effects.
    Perhaps there ought to be a check list for this.

    What I’d like to know is this; why not do the experiment again, this time making absolutely sure they’re taking into account all relativistic effects, and see if the results are the same.

    After all, isn’t that part of science? To be able to repeat an experiment and check the results against previous runs?

  12. Brian Utterback

    I don’t understand how the GPS satellites reference frame enters into the picture. According to the original paper, the two timing units were calibrated and set at the Swiss Metrology Institute and then moved to the locations at CERN and LNGS. They were then used to set a portable device which was moved from one lab to another, and the times compared. The portable device is then moved back to the first lab and the time there compared again. The device at each lab is time locked with a Cs reference frequency. The GPS satellite is used to provide the timestamp to approximately a 100ns accuracy, with the additional accuracy to within 2.3ns provided by the Cs frequency source. Since the Cs frequency source has nothing to do with the GPS time, I don’t see how the satellite reference frame can possibly have anything to do with the discrepancy.

  13. frag971

    The plot thickens!

  14. Jeremy

    When I first heard about this I rushed out and filled my gas tank with neutrinos to see if I could make my car go faster than light. Read the label on the jar wrong, it was actually Nutella that I filled my tank with.

    I need a new car now.

  15. Shalev

    “The entire flight time of a neutrino from Switzerland to Italy is only about 2.4 milliseconds,”

    Is that number correct? I have no interest in math, but 2.4 thousandths of a second is a very long time in the realm of Teeny Little Super Physics, isn’t it? That sounds pretty slow for a Neutrino.

    Edit: never mind – movement at the speed of light covers about 447 miles in that time, which sounds about right for a distance between Switzerland and Italy (depending on what part of Italy, I guess). :)

    Shameless plug, I’ve been reading “Death from the Skies” on the household iPad today and I’m still a little bit in shock that Neutrinos are such a big factor in Supernovae… Phil, you need to write more books. I had no idea that Neutrinos did anything other than baffle people.

  16. DLC

    This certainly seems probable. It may not be the case, and the original investigators seem confident they accounted for all confounders and errors, but I also remember a certain space telescope which had a nasty case of short-sightedness due to a simple error. I think the CERN/Opera team need to rework the numbers and re-run their experiment a few times. Perhaps a second and third group of scientists need to replicate this experiment de novo. It’s still interesting, but right now I can’t help but think of Cold Fusion.

  17. A J

    Didn’t read all those papers. Just wondering, did they consider that neutrinos go straight through the curve of the earth, as the distance between the two places is measured along the surface of the globe? Or did they take this into account also…?

  18. Pete Jackson

    It certainly is clear that all the data reduction and corrections need to be published in excruciating detail (or at least be made available on line) so that all can be sure that everything was considered. And they need to be sure what relativistic ajustments are already built in to the GPS results

  19. Steve

    Thanks Phil, a good explanation. I was hoping it would disprove climate change, but you can’t have everything*

    *sarcasm

  20. Chris

    So does this mean climate change is real now?

  21. @edwardv: “Could the supposed error have been in the other direction and the measured speed slightly slower than the actual speed? How would an error like that have been suspected or identified?”

    It’s a bit confusing, sometimes people say “speed of light” when really they mean the constant “c”. They aren’t the same thing. The constant c isn’t really the speed that light travels, instead it is ‘the speed that light travels in a vacuum’. What makes it doubly confusing is that light is often slowed below c, and we know of many things where things can actually travel faster than light travels through a given medium.

    Also, c isn’t a measured value, it actually ‘pops’ out of of some fairly basic electromagnetic equations (Maxwell’s equations). Most of the past century’s physics (including relativity) are based heavily on Maxwell’s equations, and speeds faster than c simply break those equations.

    The past century’s physics (and especially relativity) work so very well, that it’s hard to imagine how Maxwell’s equations (and all those derived from them) can work so perfectly in so many ways, while at the same time be very fundamentally broken with regard to “c”.

    Especially since the purported violation is *so incredibly close* to the exact value the mathematics expects for c, it seems far more likely that there’s a slight error in the measurement of the neutrinos.

    That said, everybody’s looking into this, and while super skeptical, just about everybody is secretly hoping that the news turns out to be true!

    If you’re interested, I’ve written a little more about it here:

    Point-Five Past Lightspeed
    http://www.isthisyourhomework.com/point-five-past-lightspeed/

  22. Did they also take into account the distances that CERN and OPERA are from the Earth’s center of mass?

  23. Tara Li

    I still note that:

    1) GR/SR does not deny the possibility of particles moving faster than light – as far as I have read, it only denies the possibility of particles with a non-zero rest mass moving *AT* the speed of light. This has long been an admitted loop-hole, often used by SciFi authors to have a ship accelerate to very near the speed of light, then “quantum jump” over, where they would then actually decelerate to move faster.

    2) This feature of tachyons actually moving faster as they lose energy also seems to be a possible explanation for the discrepancy between this experiment and the 4 hr advance of neutrinos from SN1987a – it seems extremely likely to me that neutrinos formed in the core of a supernova would have much more energy to them, and therefore that they would travel closer to the speed of light, than neutrinos from one of our particle accelerators.

  24. Sindragosa,

    They do automatically take it into account for purposes of finding of locations. That doesn’t work for timing which isn’t normally done automatically.Tara,

    Tara,
    That doesn’t work. We have estimates for the energy levels of the SN 1987A neutrinos. They are orders of magnitude less energetic than the neutrinos produced by OPERA.

  25. David

    His use of than and then are perfect. Anyway, why do you have to be so pretentious to correct such a small error even if he did make it?

  26. Mike L.

    Scientists at CERN have claimed to have accounted for such factors and discrepancies outlined out in Ronald A.J. van Elburg’s paper. I think a lot of people in this field are very anxious and frightened about this experiment proving true because it would require a fundamental rewrite of modern science.

  27. JC

    It’s probably 100% likely they accounted for this, but part of me wonders if it’s something incredibly simple, like they mis-estimated the time it takes for the detector to register a ‘hit’ and the resultant electrical signal to travel down some cable to a computer that then has to record that event.

  28. J

    How far does light travel in 60 billionths of a second?

    Do we know precisely how fast light travels at one atmosphere? Can we verify the distance using a laser?

    Would it be possible to perform this test in space?

  29. The thing I find surprising is how much attention that particular preprint is getting. There are many papers on the arxiv about this topic, and this one (by a person in a Department of Artificial Intelligence, mind you, not physics) seems to be getting major play. It may be right for all I know, but it’s pretty weird that people pay so much attention to a paper like this because it happened to be highlighted in the Technology Review arxiv blog. As I’ve written previously, the quality control standards on the TR arxiv blog are spotty at best. They pick stuff that sounds sensationalistic, not necessarily things that are mainstream or likely to be correct.

  30. Salvador

    Could the fact that the earth moves through space explain the change? The rotation of earth may have not been suficient.

  31. Electro

    If e=mc2 is wrong, then our space probes would not arrive where we send them, our cell phones would not work, our nuclear reactors would generate no power, our nuclear bombs would not work and the Sun would not shine…..e=mc2 is right and does not allow FTL…someone will figure out the error.

  32. Parlyne

    Having read the paper in question, it looks to me like the author ignores the fact the the distance relevant to this effect is not the full baseline of the experiment, but the projection of the baseline in the satellite’s direction of motion. This means that the 32 ns he calculates is just an upper limit. In particular, it’s even possible for a GPS satellite to be traveling perpendicular to the experimental baseline. So, at most this effect, if unaccounted for, would broaden the observed time-of-flight distribution, rather than shift it.

  33. thought
    The problem is to send and to recieve.
    The rest is irrevelent.

  34. Jack

    I like Brian’s comments about synchronizing two clocks, then moving one of them to the other site and back again at the end. However, doesn’t the action of moving them cause relativistic events to occur?

  35. Radwaste

    Considering that the SI unit, “second”, is defined as the interval taken by 9192631770 oscillations of a Cs-133 atom between two hyperfine ground states, I recognize that a) people in the biz might know the factors likely to affect timing, and b) I’m not going to be the one discovering that decaf coffee in the office was the cause of an error.

  36. Gus Snarp

    Just be sure to post another story on this when it’s all a bit more finalized, since I’m certain most of the media will never mention it again.

  37. Mike Saunders

    I don’t think measuring the timing is the problem. Its pretty easy to measure down to the femtosecond. This is going to be pretty tough to figure out, 60ns is a really small amount of time, but its also a huge amount of time. Its fun to see these two different domains come clashing together like this though.

    #18: I doubt its that. In my electro optics setup I can measure the time it takes accurately because the source and the detector is coupled. When I set something up I do a back of the envelope calculation just for a sanity check (going from coax->waveguide->freespace and back again) and I’m usually within 200ps or so. I imagine they do it with much more rigor than I do.

  38. jack21222

    This is my favorite paper on the neutrino thing, if only for the abstract:

    http://arxiv.org/abs/1110.2832

    Title: Can apparent superluminal neutrino speeds be explained as a quantum weak measurement?

    Abstract: Probably not

    This paper is by the same author who won an Ignobel for levitating a frog.

  39. VinceRN

    “Most scientists were skeptical”? If a scientist saw this single result with a century of results supporting relativity against it and wasn’t skeptical, I would question his right to that title.

    My bet is still on relativity, but how cool would it be if that were wrong?

  40. Jess Tauber

    For those of us living in the Great Simulation, this is one of those times where the design shows its imperfections, similar to those in the Star Trek universe when we see patches of reality show through what the Holodeck programmers would have us believe. Frankly I’m tired of being stuck in here. I wanna see the real world.

  41. Elgin

    Taking the low end of their results (53ns too fast, I think) and extrapolating a bit … or a lot. The neutrinos detected before the optical light of SN1987A would’ve have been here 3.6 years earlier, not 3 hours. So it doesn’t very well match older data we have on neutrinos traveling to begin with; so I’m sure they’ve just missed something somewhere.

  42. Jesse

    Just to be clear- uploading a pre-print to arXiv does not count as “publishing” a paper. It has not been peer reviewed, and should be considered as such.

  43. Iggy

    The neutrinos travelled from CERN to OPERA in a straight line, right? If so, their travel took them at least a couple of kilometers underground (because of the curvature of the earth) and also beneath the alps. It seems to me that this would cause the force of gravity acting upon them to vary significantly during the journey and in turn the gravitational time dilation. The same goes for the density of the rocks the neutrinos passed through. I suppose all this was taken into account?

  44. Jake

    I think OPERA should be given a little more credit. Relativity is the first thing everyone thinks of, so of course, the experiment took it into account. It’s a little insulting to assume that hundreds of physicists with access to any of the worlds experts can’t do a well understood GR problem. Also, the time of flight wasn’t measured with GPS, so why is this article making so much noise on the web?

  45. Robin

    Uhm, just a reminder: IF the results of the neutrino experiment are confirmed, it does not mean that SR is wrong. It just means that it is incomplete. There is a huge difference between the two.

  46. Dav

    I am even more skeptical of this GPS error paper than the original experiment. The CERN/OPERA scientists are not amateurs and this would be a pretty obvious glitch to overlook. Especially, if you were struggling with what your incredible results would have to say about relativity if true. I don’t think you would fail to consider it in your investigation.

    I suspect the fellow who wrote the paper was a lot like the rest of us and had no idea of the actual parameters, depth and complexity of the CERN/OPERA investigation. So, without significant information about all that went into the data collection and analysis, his paper like the rest of all of our comments, is pure speculation. Nice try though.

    Interesting tidbit nonethless, thanks.

  47. GPS clocks are speeded up to run at the same rate as ground clocks; speeded up because the General relativity effect of lower gravitational potential at their altitude is more important than the velocity difference. It sounds like the experimenters have been very careful with the ground time standards; so let us for now take that as not being the source of the discrepancy.
    GPS distance measurement usually involves calculating the time of flight of photons from several satellites at know positions, dividing by the speed of light, and triangulating the results. As GPS satellites are on different velocity vectors, the relativistic effects of their motions are normally blurred. But to achieve great accuracy, only one satellite moving in a polar orbit about parallel to the neutrino path may have been used. The trouble here is that from the viewpoint of a single GPS satellite moving parallel to the experiment path, those carefully synchronized clocks on the ground are not synchronized–different frames of reference. I think what the Netherlands scientists are saying is, essentially, that an assumption that the ground clocks were synchronized with the GPS clocks would effectively put the distance calculations in the GPS frame, so that the distance intervals are contracted instead of dilated, resulting in a relativistic path length correction in the wrong direction and “early” arrival. It’s effectively a sign error. But given that my data is blogs and unreviewed preprints of papers lacking sufficient details, this conclusion is very uncertain.

  48. I would be very surprised if this turned out to be the correct explanation. Synchronizing clocks on different points on the surface of the Earth using GPS (which involves several relativistic corrections) is pretty standard nowadays, and people at OPERA aren’t exactly dumb. You can check out the relevant theory at

    http://relativity.livingreviews.org/Articles/lrr-2003-1/

    where among other things you find that all clocks on the surface of the Earth tick at the same rate (the difference in time dilation coming from the different rotation speeds at different latitudes is exactly cancelled by the difference in gravitational time dilation coming from the nonsphericity of the Earth).

  49. Parlyne

    @Iggy (#45) those effects are something like 5 orders of magnitude too small to explain the observed discrepancy.

  50. alfaniner

    “Neutrino.”

    “Who’s there?”

    “Knock, knock.”

  51. Robin,

    More than that, we know that SR doesn’t describe all of reality already (hence things like GR and quantum mechanics). There’s nothing in SR that actually goes wrong if one has superluminal particles. SR only has a problem if a) particles with mass travel at the speed of light in a vacuum or b) particles without mass travel at a different speed.

    This result is almost certainly wrong, but fully consistent with SR by itself.

  52. Electro

    Pretty sure they have established that neutrinos have rest mass. Not much, but it is
    there.

  53. SkyGazer

    “Was relativity doomed? ”
    Nope, but anti-science-skeptics are.

  54. Richard B

    “Basically, what Einstein found is that the speed of light is the same for all observers…”

    Decades before Einstein was born in 1879, Maxwell’s work had firmly established light speed a constant in the theoretical sense. And by 1887 Michelson-Morley had experimentally demonstrated light speed’s independence from emitter/observer motion. By 1900, c was the symbol accepted in physics to denote the constancy of electromagnetic radiation in vacuum. Throughout 1895-1904, Henri Poincare discussed the exact method of clock synchronization using fixed-speed light signals which was later borrowed by Einstein and published as his own, without attribution.

    It’s interesting and surprising that the peculiar, ahistoric narrative of outsider-patent-clerk-as-sole-hero/founder-of-Science’s Second Revolution continues even within the realm of ostensibly evidence-based science. One is mightily pressed to uncover even a single facet of the principle of relativity which Einstein uniquely “found” in 1905 that hadn’t already been fully developed — in the published, archived, mainstream scientific literature — by Lorentz and Poincare.

  55. Jess Tauber

    If the measured neutrino speed was dependent on UPS, rather than GPS, it might arrive weeks later than light, if it gets there at all….

  56. SkyGazer
  57. Stathis Dimopoulos

    The Dutch physicist is WRONG. The Caesium clocks were syncronized using a ground link and the timings were verified by two indepenent metrology Institutes . Another person in Wired magazine was kind enough to point it

    quoting the CERN paper:
    “A key feature of the neutrino velocity measurement is the accuracy of the relative time tagging at CERN and at the OPERA detector. The standard GPS receivers formerly installed at CERN and LNGS would feature an insufficient ~100 ns accuracy for the TOFν measurement. Thus, in 2008, two identical systems, composed of a GPS receiver for time-transfer applications Septentrio PolaRx2e operating in “common-view” mode and a Cs atomic clock Symmetricom Cs4000, were installed at CERN and LNGS. They were calibrated by the Swiss Metrology Institute (METAS) and established a permanent time link between two reference points (tCERN and tLNGS) of the timing chains of CERN and OPERA at the nanosecond level. The difference between the time base of the CERN and OPERA PolaRx2e receivers was measured to be (2.3 ± 0.9) ns. This correction was taken into account in the application of the time link.

    The relative positions of the elements of the CNGS beam line are known with millimetre accuracy. When these coordinates are transformed into the global geodesy reference frame ETRF2000 by relating them to external GPS benchmarks, they are known within 2 cm accuracy.

    The high-accuracy time-transfer GPS receiver allows to continuously monitor tiny
    movements of the Earth’s crust, such as continental drift that shows up as a smooth variation of less than 1 cm/year, and the detection of slightly larger effects due to earthquakes.”

    Thankfully the dream of the FTL travel is still alive.

  58. I suspect this won’t be settled until the experiment can be repeated in an inertial reference frame — probably first in LEO, then probably Earth–Sun L1.

    On the other hand, I think I remember some experiments showing that light moves through some materials faster than c. It was later shown that it was only the group velocity, not the wave velocity (or the other way around) was faster than c, and consequently information was not traveling faster than c. Since this experiment (apparently) measured clouds of neutrinos rather than individual neutrinos, maybe by some kind of particle/wave duality these clouds of neutrinos are traveling faster than c, but the neutrinos themselves are not. Sounds weird but I’ve heard weirder things come out of quantum physics.

  59. I thought it might be something silly like measuring the distance between the two point based on a flat Earth rather than the more direct route the cuts under the curve. But that would probably create a discrepancy greater than 60 ns.

  60. Runi Sørensen

    I recently started my study of physics at the University of Copenhagen (want to be an astronomer btw).

    Anyway, since the Neutrinos arrive in a cloud instead of individual particles, couldn’t the explanation be that we are measuring the group velocity of the wave (matter is also a probability distribution) instead of the signal velocity (which contains the information). Since group velocity can exceed c, this might be the explanation?

    If anyone know more about how these concepts apply to the experiment, I would like to know :)

  61. Dav

    One other point I’d like to make (and would be interested if others feel the same way) is with regard to the hope that the FTL neutrinos are real. During college and grad school I found that many professors, and the then current physics graduates, seemed to take a great delight in Einstein’s rigid view that nothing travels faster than light. Any time hypothetical/theoretical conversations ensued they would dismiss any concepts that would require FTL travel with a smile, wave of their hand and a sage quote paraphrasing Einstein.

    I really found it quite irritating but, unfortunately, I never had a decent come back other than a famous quote from Arthur C. Clarke, to wit: “If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong”. Great quote but very light on evidence. So, I was very excited at the possibility that the CERN/OPERA experiments have shattered the speed limit once for all. However, I also realize that if the past is any guide, it will just end up as another error-induced finding recorded as a footnote in some obscure history of science encyclopedia.

    Nonetheless, even if this turns out to be just one more erroneous finding, I will still hope for the demise of the FTL speed limit in my lifetime. In many ways I think it has restrained scientific thought, serious research, funding and even casual bull sessions between physics-minds.

    No matter what the outcome, it is my opinion that we need to devote much more scientific effort to trying to break Einstein’s limit. Until we do, our limited physics will always keep our official aspirations small, our human travels limited to our tiny solar system, our professors dismissive and will be a source of constant chafing under a number of collars.

  62. DMason

    I’m not a physicist, a scientist, or a psychiatrist but, one thing I’ve noticed is people become very threatened when their understanding of the world and universe is threatened.

    This includes any experiment challenging Einstein’s “Theory of Relativity.” People take great comfort in it — like they take comfort in the Bible. Einstein’s “Theory of Relativity” provides an absolute so they don’t have to question anything.

    All I know is what I read about the physicists/scientists at CERN. They claim to have repeated the FTL/neutrino experiment more than 15,000 times before they went public with their findings.

  63. BarerMender

    Einstein didn’t “find” that the speed of light was constant for all observers. He assumed it. It was one of his three basic assumptions. So far as I know, it’s never been proven. There was evidence that supported it and evidence that contradicted it.

  64. christos dimitrakakis

    Yes, the published paper really does not have a lot of details. The description of the statistical model and methodology is especially imprecise.

  65. Nigel Depledge

    According to the report in New Scientist from a couple of weeks ago, the OPERA team spent 3 years trying to understand this discrepancy before throwing it open to the particle-physics community at large.

    You can be sure the explanation ain’t something simple.

  66. Nigel Depledge

    Dr Flimmer (8) said:

    That might cool down some folks here and there. I know of a group of physicists who calculated some weired stuff with neutrinos taking a short-cut through an assumed fifth dimension.

    IIUC, that fifth dimension is not so much assumed as predicted by string theory. Some commenters are suggesting that this result is the first piece of evidence to distinguish string theory from other theories of particle physics.

  67. Nigel Depledge

    @ Grand Lunar (11) –

    What, you think they did this experiment just the once?

  68. Nigel Depledge

    DLC (16) said:

    Perhaps a second and third group of scientists need to replicate this experiment de novo. It’s still interesting, but right now I can’t help but think of Cold Fusion.

    There is a huge difference between this result and Fleischman and Pons’s “cold fusion”. In this case, the team are (in essence) saying “well, we’ve tried our best to nail this down as an experimental or maths error, and we can’t, so can anyone else spot where we’ve gone wrong?”, whereas Fleischman and Pons insisted they had discovered room-temperature fusion despite the heaps of criticism that their methodologies received. And even after other labs had failed to reproduce their result.

  69. Nigel Depledge

    Tara Li (24) said:

    2) This feature of tachyons actually moving faster as they lose energy also seems to be a possible explanation for the discrepancy between this experiment and the 4 hr advance of neutrinos from SN1987a – it seems extremely likely to me that neutrinos formed in the core of a supernova would have much more energy to them, and therefore that they would travel closer to the speed of light, than neutrinos from one of our particle accelerators.

    First, tachyons are fictitious (i.e. they don’t form a part of any real theory of particle physics).

    Second, the neutrino – light delay from SN1987a is understood.

    Third, the neutrinos generated at CERN had about 100 times the energy of the neutrinos generated in SN1987a. Yeah, CERN has some pretty hot particle accelerators.

  70. Nigel Depledge

    Mike L (27) said:

    Scientists at CERN have claimed to have accounted for such factors and discrepancies outlined out in Ronald A.J. van Elburg’s paper. I think a lot of people in this field are very anxious and frightened about this experiment proving true because it would require a fundamental rewrite of modern science.

    Not so. It may be the first bit of evidence for the existence of additional dimensions.

  71. Nigel Depledge

    Jack (36) said:

    I like Brian’s comments about synchronizing two clocks, then moving one of them to the other site and back again at the end. However, doesn’t the action of moving them cause relativistic events to occur?

    Well, the acceleration of the clock will cause a discrepancy, but when it is accelerated at the miniscule values achieved by human machines, the discrepancy is not anywhere near large enough to account for the full 60 ns.

    IIUC, the team could only account for about 10 ns of error by adding up all the sources of error they could identify.

  72. Joakim Rosqvist

    Maybe there was a small burst of neutrinos 60 ns before the big burst and the detectors at the sending and receiving stations have different sensitivity so that the clock starts when the big burst is sent and stops when the small burst arrives.

  73. Nigel Depledge

    Dav (63) said:

    No matter what the outcome, it is my opinion that we need to devote much more scientific effort to trying to break Einstein’s limit. Until we do, our limited physics will always keep our official aspirations small, our human travels limited to our tiny solar system, our professors dismissive and will be a source of constant chafing under a number of collars.

    It’s not like the sound barrier. As far as we can tell, the speed-of-light limit is a fundamental feature of the universe. Thus, no amount of effort will break the limit.

  74. Dav

    Regarding breaking the light speed limit,

    Nigel Depledge (72) said:

    “It’s not like the sound barrier. As far as we can tell, the speed-of-light limit is a fundamental feature of the universe. Thus, no amount of effort will break the limit.”

    Thanks for the feedback Nigel. The operative statement here is, “As far as we can tell…”. Think of how many times through scientific history people have made assertions similar to your own only to have to eat their words later. I very much hope you are one of those that gets to enjoy such a snack (however, I suspect that if queried, you wouldn’t mind the extra meal, presuming faster than light speed was confirmed).

    Fortunately, there are always those who either plug along, inch-by-inch and others that step outside of conventional wisdom and pursue their own path. Most of the time the wildcards go down in flames while the pluggers go on to do good science. But, frequently enough, one of the unconventional thinkers succeeds either through lucky accident or initial intuition and science takes a leap forward. I admit that the naysayers serve an important purpose. But in the end I think most of us truly enjoy new science and the wonders that it brings.

    By the way, I wouldn’t get hung up on the terms used to describe going faster than light. No one that I know considers faster than light speeds analogous to breaking the sound barrier; implying that my interest in seeing faster than light speeds was analogous, was a bit condescending.

    I’ve been around quite a long time and am fortunate to have lived to see many sacred cows slaughtered. Entanglement made for a wonderful barbecue. I hope all of us live to see FTL.

  75. Very interesting.

    What about Dark Matter? What about the Universal Constant thingie?

    Anyway, I’ve got a new theory of physics mostly worked out that will explain this. I’ll get back to you as soon as I’ve got the math done….

  76. Tim G

    Several years ago, “superluminal” quasars presented a problem. They led many astronomers to postulate that they weren’t as distant as the general consensus had them to be. However, their seemingly impossible apparent speeds were explained as a relativistic illusion that resulted when the quasars emitted jets that traveled near the speed of light and were oriented near our line of sight.

    I’m under the impression that the problem of the superluminal neutrinos is much more intricate but maybe an explanation for the results will be simpler.

  77. MCR

    They didn’t use the GPS clocks to time the experiment, they used cesium atomic clocks and adjusted for time dilation relative to their altitude on the Earth (time moves at different rates based on your position and altitude due to the strength of gravity). If you read the original paper they clearly state that they had problems with the margin of error introduced using the GPS signal for timing and moved to this system as it was far more accurate and precise.

  78. epic

    this all hinges on one thing; that GPS was the only method used to measure the distance. Which is not the case.

  79. edwardv

    @MrTemple (#22)
    My point is they were probably expecting something less than c, but how much less? Did they know the energy the neutrinos should have had and the speed they should have had? Or were they trying to measure that speed not knowing what it would be? How much under the speed of light would alarm them, or be wrong and not alarm them?

  80. Time to spool up the FTL.

  81. CB

    My point is they were probably expecting something less than c, but how much less? Did they know the energy the neutrinos should have had and the speed they should have had? Or were they trying to measure that speed not knowing what it would be? How much under the speed of light would alarm them, or be wrong and not alarm them?

    They knew how much energy the neutrinos should have, but the actual speed they would travel would depend on the neutrinos’ mass, which is currently unknown. They would probably have been alarmed if they had measured a speed that implied a mass greater than the experimental upper bounds that have been established — and that’s a very, very small mass (like one millionth the mass of an electron).

  82. CB

    Also, c isn’t a measured value, it actually ‘pops’ out of of some fairly basic electromagnetic equations (Maxwell’s equations). Most of the past century’s physics (including relativity) are based heavily on Maxwell’s equations, and speeds faster than c simply break those equations.

    This is true, but these days I believe the most precise values of c are measured directly, rather than from measurements of the vacuum permittivity and permeability.

  83. JoeArnold

    Im not a physicists but couldn’t a solution be firing a cloud of photos and calculate how long it takes. This wouldn’t show where the error comes from initially but it would prove if the neutrinos were indeed traveling faster than light. It wouldn’t matter if they didn’t get exactly 299792458 m/s as long as the time was less than the neutrinos time, the dilemma would be taken care of.

  84. Nigel Depledge

    Dav (76) said:

    Thanks for the feedback Nigel. The operative statement here is, “As far as we can tell…”.

    These are important words, but they do not by any means mean that there is a high probability that the speed limit is breakable.

    Think of how many times through scientific history people have made assertions similar to your own only to have to eat their words later. I very much hope you are one of those that gets to enjoy such a snack (however, I suspect that if queried, you wouldn’t mind the extra meal, presuming faster than light speed was confirmed).

    Well, on the one hand, my statement is correct, because I included that phrase you have highlighted, so there will not be any need to eat those words. However, you surmise correctly that I would be delighted for humanity to discover FTL travel. I just don’t see it happening any time this millenium.

    Fortunately, there are always those who either plug along, inch-by-inch and others that step outside of conventional wisdom and pursue their own path. Most of the time the wildcards go down in flames while the pluggers go on to do good science. But, frequently enough, one of the unconventional thinkers succeeds either through lucky accident or initial intuition and science takes a leap forward.

    Can you think of any examples?

    I can only think of Watson and Crick, who (arguably) stole Rosalind Franklin’s X-ray data to get a head-start.

    All of the other “wildcards” I can think of either did their homework to get good data to support their hypothesis (i.e. they plugged away to get the goods) or they went down in flames because their ideas did not stand up to scrutiny.

    I admit that the naysayers serve an important purpose.

    I think your use of the term “naysayer” is very negative. I’m not saying “nay” here – I’m saying that our best understanding is that FTL travel (relative to local space) is impossible.

    But in the end I think most of us truly enjoy new science and the wonders that it brings.

    Agreed.

    By the way, I wouldn’t get hung up on the terms used to describe going faster than light. No one that I know considers faster than light speeds analogous to breaking the sound barrier; implying that my interest in seeing faster than light speeds was analogous, was a bit condescending.

    Your comment made it seem as though you considered breaking the lightspeed limit to be merely a matter of trying hard enough. In that sense your comment implicitly drew an analogy between breaking the lightspeed limit and breaking the sound barrier (which was just a matter of trying hard enough). So, I do not agree that taking this meaning from your comment and making it explicit was condescending.

  85. Gary Ansorge

    I still see no mention in the lit. about indeterminacy, ie, during the neutrinos transition from a muon to a tau neutrino, its position is indeterminant. Thus, they could be further along their path after the transition than could be accounted for by mere velocity. Perhaps increasing the neutrino energy will show a larger time discrepancy.

    Gary 7

  86. Eddie Maalouf

    Did anyone investigate the “particle/wave” duality state of the neutrino cloud as the cause for the timing offset?

    In the slit paper experiment, single neutrinos registered as waves. The neutrinos’ speed was not measured but its wave-function was studied as the cause.

    Did the guys at CERN also reference QED (Quantum Electrodynamics theory — Richard Feynman – Nobel prize in the 60’s) as a possibility?? It postulates that particles take multiple paths (simultaneously)?? Could that, coupled with the wavefunction measurements of the neutrino clouds explain the ghostly time difference??

    Curious???

  87. Captn Tommy

    Okay… a neutrino may or maynot be traveling faster than the speed of light. What about the wave amplitude factor where the photon, which does travel Light speed is actually traveling faster than, because of the pitch to pitch linear distance traveled (along the sine wave) is longer than the pitch ( the distance from peak to peak) distance which defines the SoL.? Are we actually going faster or slower ? or is everything Relative.

    Or does it matter when my Dodge Neon gets such poor mileage anyway.

    Irregardless

    Captn Tommy

  88. Dav

    Nigel,

    Thanks again for the comments. I am not a starry-eyed grad with a newly-minted doctorate and I don’t kid myself that the likelihood of the neutrino speeds proving out to be FTL is decidedly slim. However, I have not set a time or date when I think we will be ready to discover something able to exceed light speed. Furthermore, since entanglement went from theory to fact, I was/am comfortable that we were POSSIBLY observing one of two phenomena. The first being FTL communication (in the physical sense). The second being some other dimension where the particles remain connected despite being separated here in our observable four.

    In my mind, it really doesn’t matter which because either way, it demonstrates that the net result from our perspective is FTL speeds. Of course I have heard many of the hypothesis regarding how entanglement communication is not technically faster than light. But, as far as I am concerned, something has already achieved such speeds and it is up to us to sort out how.

    Regarding persons having unconventional flashes of understanding rather than slow plugging away (or combined with slow plugging away), I would say that it is somewhat a matter of interpretation. I would begin with a 26 year old patent clerk publishing an extremely radical paper in 1905. If that wasn’t a leap forward by someone not plodding along, I don’t know what is. Michael Faraday with little formal education discovering and elucidating diamagnetism, induction and establishing the basis for experimental science. Gregor Mendel discovering inheritance, and establishing the existence of dominant and recessive genes without any evidence or understanding of molecular genetics (and being ignored by mainstream science). Kepler’s flash of genius regarding planetary motion (whether he was really drunk when it occurred really hasn’t been established). The list goes on. Most of them had periods of time where they were not believed because there were accepted contrary theories and/or no previous supportive evidence.

    Finally, my comment regarding the need for more ‘scientific effort’ regarding the pursuit of FTL speeds simply means that just because the evidence for it goes against the current thinking of many mainstream scientists does not mean we should stop looking. We have nothing but statistical data to presume there is life on other planets. However, there is no doubt in my mind that there is. I am not the only one that thinks we should keep looking despite the fact we have not found any physical evidence. I would argue that indicating a need for more scientific effort in TRYING to break Einstein’s limit is quite a bit different than saying we CAN break it with more ‘hard work’.

    However, I will give you the benefit of the doubt that you truly interpreted what I said as you described. But now you know that was not what was meant. Oh, and naysayers ARE critically important to science….just as those who are willing to think outside the mainstream are. It is the give and take between these two perspectives that can produce very good science. You appear to enjoy the role on here of the mainstream advocate (though I make this presumption with limited evidence). I, on the other hand, sometimes enjoy the edge where there are few, if any, mainstream paths laid out. I also tend to encourage other scientifically-educated persons to stretch beyond their comfort zone once in a while.

    Anyway, I enjoyed the exchange and I appreciate your perspective. Thanks again.

  89. Gerry

    Thanks Phil. Would you take a moment to clarify a small point? I’m told that light cannot travel faster than the cosmological speed limit (“why does E=mc2?” by Cox and Foreshaw). We are always told that nothing can travel “faster than the speed of light” but isn’t it that nothing can travel “faster than the cosmological speed limit?”

    Is it possible that the cosmological speed limit is a bit higher than the speed at which light can travel, yet E still equals mc2? (c of course being the higher cosmological speed limit).

    Gerry

  90. NobodySpecial

    #86 – unfortunately these two experiments are both underground and several hundred miles apart with Switzerland inconveniently in the way making it rather hard to shoot a beam of light between them.

    And even if you could the variations in the apparent speed of light in the atmosphere (due to temperature, humidity and pressure variations) are much larger than the effect you are measuring,

  91. Nigel Depledge

    Dav (92) said:

    Regarding persons having unconventional flashes of understanding rather than slow plugging away (or combined with slow plugging away), I would say that it is somewhat a matter of interpretation. I would begin with a 26 year old patent clerk publishing an extremely radical paper in 1905. If that wasn’t a leap forward by someone not plodding along, I don’t know what is.

    Actually, most of the components of SR were already extant, courtesy of Maxwell and Lorentz, although whether or not Einstein knew this is open to interpretation. Einstein’s brilliance was not merely in pulling together the various ideas about relativity into a single theory, but was also in doing the maths to prove it. So, although the initial insight may have been a flash of brilliance, doing the legwork to demonstrate the validity of the idea could indeed be considered to be plugging away at it.

    Michael Faraday with little formal education discovering and elucidating diamagnetism, induction and establishing the basis for experimental science.

    But he was hardly a wildcard, and his discoveries and insights came from years of painstaking experimentation.

    Gregor Mendel discovering inheritance, and establishing the existence of dominant and recessive genes without any evidence or understanding of molecular genetics (and being ignored by mainstream science).

    If ever there was a good example of a “plugger”, it is Mendel. It took him years to establish some understanding of inheritance, and further years to accumulate the data to prove his ideas. And his work was only overlooked because he published in a language other than French, German or English. And his work was only overlooked temporarily, because otherwise we would not have heard of him. Incidentally, I recommend a visit to the Mendel Museum in Brno (Czech Republic) – it is quite fascinating. Molecular genetics was not really relevant, since his understanding of heredity predates it – rather, molecular genetics explains the “how” of Mendel’s “what”.

    Kepler’s flash of genius regarding planetary motion (whether he was really drunk when it occurred really hasn’t been established).

    I don’t know much about Kepler, but IIUC, he did his best work using Brahe’s painstakingly-accumulated data, so he might belong in the “half-and-half” category with Watson and Crick.

    The list goes on. Most of them had periods of time where they were not believed because there were accepted contrary theories and/or no previous supportive evidence.

    And my point is that most of these people (with exceptions as noted) did an awful lot of work to acquire the data (or to assemble the proof) to demonstrate that their idea was correct.

    It is very rare for a major discovery in science to rest on a single moment of inspiration. More often than not, that flash of inspiration must be supported by reams and reams of data. Wegener is a good example here : he was kind-of right (although his proposed mechanism was wrong) but he did not have enough data to support his ideas so he was – metaphorically – shot down in flames.

  92. Nigel Depledge

    Dav (92) said:

    Furthermore, since entanglement went from theory to fact, I was/am comfortable that we were POSSIBLY observing one of two phenomena. The first being FTL communication (in the physical sense). The second being some other dimension where the particles remain connected despite being separated here in our observable four.

    I don’t want to get into a discussion of entanglement here – partly because I don’t think it’s relevant, but mostly because I have not understood any explanation of how entanglement works.

    However, regarding the postulated extra dimension that might have provided a shortcut for these neutrinos : if this is indeed what has happened, then Einstein’s speed limit remains intact (the neutrinos took a shorter route than was available in our four-dimensional spacetime) and it may be the first piece of evidence in support of string theory.

  93. Heather

    Why do we say nothing can travel faster then light? Wasn’t there an inflationary period just after the big bang, when we are told the universe expanded faster then light?

    So it does seem something can go faster then light!

  94. Nigel Depledge

    Dav (92) said:

    Finally, my comment regarding the need for more ‘scientific effort’ regarding the pursuit of FTL speeds simply means that just because the evidence for it goes against the current thinking of many mainstream scientists does not mean we should stop looking.

    It’s not that the evidence for FTL neutrinos goes against the “current thinking” of many mainstream scientists – it’s that the result that hints at FTL neutrinos contradicts one of the best-established theories of modern science. Any credible scientist will be both excited and sceptical about the OPERA result. The OPERA team themselves are both excited and sceptical – they are not ready to rule out some mistake in their calculations or experimental set-up (though, IIUC, they have been as careful and as thorough as anyone could wish them to have been).

    In terms of whether or not we should “look” for FTL phenomena, I’m really not sure what you mean here. Since there is pretty nearly no theoretical basis for FTL travel of particles, how could one design an experiment to look for FTL phenomena?

    However, if you mean we should keep an open mind when an observation surprises us like this one from OPERA has done, then I agree, provided it is tempered with appropriate scepticism.

    We have nothing but statistical data to presume there is life on other planets.

    Well, not really. We have no evidence one way or another, so all we have amounts to educated guesswork.

    However, there is no doubt in my mind that there is.

    Really? No doubt at all? Why?

    Me, I have doubts. We simply do not know. I feel that at least bacterial life is likely on some other planets in our galaxy, but I have no firm evidentiary basis for this feeling, so it might be based on nothing more than wishful thinking. Am I fooling myself with an argument from personal incredulity?

    I am not the only one that thinks we should keep looking despite the fact we have not found any physical evidence. I would argue that indicating a need for more scientific effort in TRYING to break Einstein’s limit is quite a bit different than saying we CAN break it with more ‘hard work’.

    But I still do not see what you mean here about “looking” for evidence of FTL phenomena. How can you look for something that all theory suggests is impossible? For example, how would you go about searching for invisible pink unicorns?

    And I do not accept your argument that trying to break the limit does not imply a belief (or at least a strong suspicion) that the limit can be broken. To even make a beginning to such an endeavour, you would need to have at least some idea of how to achieve it. And thus you would need to have an hypothesis that permits FTL travel. And such an hypothesis would gainsay one of the most firmly-supported theories we have.

    Now, I’m not about to claim absolutely that SR is correct, but I think we can confidently conclude that it is at the very least a good approximation. In the same way that Newtonian gravitation turned out to be a special case of GR, I think SR is either correct or a special case in a broader theory.

    However, I will give you the benefit of the doubt that you truly interpreted what I said as you described. But now you know that was not what was meant.

    OK, let’s call it quits there.

    Oh, and naysayers ARE critically important to science….just as those who are willing to think outside the mainstream are.

    I still think that term sounds negative. Why not use “sceptic”? The term “naysayer” sounds like someone who will never say “yea” no matter how much evidence is presented. I think “sceptic” is a more appropriate term.

    As for “thinking outside the mainstream”, I’m not sure what you mean. A lot of crackpots try to claim legitimacy by comparing themselves to persecuted mavericks from the past (frequently Galileo) but this does not make their crackpottery any less so. Then again, many people who would clearly be identified as mainstream scientists are examining strange and wild ideas in attempts to resolve some of the biggest questions in physics. An obvious example of this is M-theory, which postulates that our universe is a 4-dimensional “brane” residing in a higher-dimensional “bulk”. M-theory has no evidentiary support at present, but it appears to be logically consistent, and it resolves some of the problems facing cosmology. And it is taken seriously by many cosmologists.

    So, how do we distinguish a mainstream physicist who is considering some wild ideas from a crackpot who is pushing a wild idea that is clearly idiotic? Why, we judge ideas on their individual merits, as science always does (even if individual scientists sometimes fail to do this). Never forget that any idea that goes against the “mainstream” must explain what is currently known at least as well as the present theories.

    It is the give and take between these two perspectives that can produce very good science.

    Well, yes and no. I think self-criticism is a most important element for any great scientist. It seems to me, from what I have read, that the OPERA team has taken a very critical view of their work, and they cannot find an error that explains the discrepancy.

    You appear to enjoy the role on here of the mainstream advocate (though I make this presumption with limited evidence).

    Well, kind of. I try to remind everyone that the theories we currently have as explanations for how the universe functions are, while almost certainly incomplete, very thoroughly tested. I feel that our present theories must at the very least be good approximations to how reality behaves. If they were not, we would have spotted it by now.

    I, on the other hand, sometimes enjoy the edge where there are few, if any, mainstream paths laid out. I also tend to encourage other scientifically-educated persons to stretch beyond their comfort zone once in a while.

    While there is merit in this viewpoint, I feel that there is often too little respect for the stuff that we have already found out. There are two main reasons why we still use SR and GR to describe and predict how the universe behaves. First, these theories ahve withstood every test we have thus far been able to throw at them. And second, no-one has come up with better explanations that are equally parsimonious to or experimentally distinguishable from SR and GR.

    Anyway, I enjoyed the exchange and I appreciate your perspective. Thanks again.

    Thank-you.

  95. #96 Nigel, #92 Dav:
    Nigel is correct about Kepler. For several years, he worked as assistant to Tycho Brahe; after Tycho’s death, Kepler inherited all of his observational data, which had been accumulated over many years.
    While Tycho was one of the greatest observers who ever lived, and compiled the most accurate tables of planetary motions of his time, he was definitely not a theoretician; he was the last “great” astronomer to reject Copernicanism, and stubbornly hold onto the geocentric world view. His own observations actually proved him wrong, but he stubbornly refused to accept it; he found discrepancies between the predicted and observed positions of Mars, and tried to explain them by inventing ever more complex “epicycles”.
    After Tycho’s death, Kepler – who was a mathematician and theoretician, and certainly did support heliocentrism – found that his observations could be explained by assuming that the orbits of the planets are elliptical instead of circular. From there, he went on to develop the Three Laws, which laid the foundation for Newton’s work on gravity.
    So Kepler’s realisation that the orbits were elliptical wasn’t exactly a sudden flash of inspiration; it was driven by the need to interpret the many years’ painstaking observations of his mentor, and to find a model which fitted the data.
    In fact, Kepler had previously formulated a completely different theory of planetary motions, which was based more on mysticism than physics – but he abandoned it when he found that it couldn’t explain Tycho’s observations. So in this sense, he could certainly be regarded as having “plugged away”; he came up with one theory, found that it didn’t work, then abandoned it and started over again.

  96. Nigel Depledge

    Heather (98) said:

    Why do we say nothing can travel faster then light? Wasn’t there an inflationary period just after the big bang, when we are told the universe expanded faster then light?

    So it does seem something can go faster then light!

    More specifically, the prohibition is against accelerating an object that has mass to light-speed relative to its local spacetime. Obviously, EM radiation travels through vacuum at the speed of light. The expansion of space does not cuase any object to accelerate relative to its local spacetime, even though the net effect of expansion is the movement of distant objects away from one another (and even without inflation, objects that are very distant can be moving apart at an apparent velocity greater than c – this is actually the resolution of Olber’s Paradox).

  97. Dav

    Nigel,

    I cannot believe that the text that I wrote just got dumped from this website. Yeah, I know better than type a long dissertation into text box, mea culpa. Normally I use Wordpad. I didn’t this time. So, I will have to try again after I get some sleep. I did/will address your points and Neils. Sorry about that.

  98. Mementum

    Hello everybody,

    Well above some comments talk about the atomic clocks used in the experiment and about GPS not being used for the timing.

    The atomic clocks (Cs4000) were actually used to provide a reference for the GPS timing (from the paper: “The Cs4000 oscillator provides the reference frequency to the PolaRx2e receiver, which is
    able to time-tag its “One Pulse Per Second” output (1PPS) with respect to the individual GPS
    satellite observations”)

    Furthermore and to give credit to the dutch paper, the PolaRx2e GPS receiver were configured in “common view” (again from the Opera paper). The common view method was developed by NIST to synchronize clocks and has one special feature to make it accurate: “Observations have to use only 1 satellite”

    Of course “common view” is expected to be used to tag events on synchronized locations with accuracy, but the authors were possibly not considering the following case:

    — Measuring the motion of a particle travelling very close to “c” (because then relativistic effects have to be fully taken into account)

    So:

    1. Yes GPS was used for the timing (please check the Opera paper if in doubt)
    2. Only 1 satellite was used for the timing (please check the Opera paper if in doubt and look for “common view”

    And I can personally imagine a bunch of scientits and some of them mentioning that GPS satellites already account for SR and GR (forgetting to mention that this “account” is simply static and has nothing to do with using a single “satellite” as a clock, which becomes a moving clock and coincidentally almost paralled to the motion of the particle)

    The dutch paper has not been refuted by CERN or Opera. Had it been so clueless as some mention, it could have been very quickly ruled out … but it has not.

  99. JB80

    @Mementum

    Actually the Elburg paper has not only been refuted it seems but dismissed by OPERA.
    http://www.livescience.com/16621-faster-light-neutrino-relativity-gps-clocks.html

    Migliozzi also asserted, “The author does not know that relativistic effects are accounted for in the GPS system.” To this, van Elburg said he is checking his facts and will follow up with additional details soon.

    So while this is a nice paper for people to jump all over I doubt it will be the reason behind FTL neutrinos being unravelled.

  100. Nick Egan

    Todays fact is tomorrows fiction

  101. Mementum

    @JB80

    Yes. GPS relativistic effects are taken into account in the GPS system. The clock of each satellite is set to compensate for SR and GR and make it deliver the same timing that a clock on Earth does (one at sea level)

    But I do believe that people are overlooking the fact that this is exactly what Special Relativity needs to come into play: two perfectly accurate clocks, each on a different inertial frame, moving relative to each other.

    Because: does a GPS satellite compensate for its relative motion to a neutrino moving at almost the speed of light? No. The compensation is just to deliver the same timing as a clock on earth.

    For the speeds that any vehicle achieves on Earth (or even in Space) the relativistic effect of time dilation is for all practical purposes as good as null.

    But the neutrino is moving at a speed close to “c”, so the effect can no longer be discarded.

    And remember: “1 satellite” because the GPS receivers used were configured in “common view”.

  102. JB80

    That’s all well and good but when you have Migliozzi who worked on the OPERA team stating publicly that it has been accounted for and that Van Elburg is wrong most likely after reading his paper and crunching the numbers himself and comparing them with their own numbers. I’m going to say that he actually might know a bit more about it than a Dutch scientist who does not have all the data at hand.

    I don’t believe this is the schaudenfreude masterpiece that people believe it to be.
    Concentrate on the ICARUS findings or better yet wait until the real expirementation gets rolling with MINOS and T2K.

    Nothing has been answered here yet and it would be premature to suggest otherwise.

  103. Mementum

    I tried adding a link to Tedd Dunn’s support of Van Elburg’s paper and criticism of Migliozzi’s answer. Google it.

    Summarising: Migliozzi is righ (as I already said above) in that a GPS satellite is adjusted to compensate for GR and SR. But the SR adjustment (the one of intereste in this case) is to compensate for the relative motion of the satellite with a point on earth.

    Because our vehicles do not reach relativistic speeds, no adjustment is needed for the speed of our thingies.

    But a neutrino travelling at almost “c” is something the SR adjustment can’t compensate for even if Migliozzi believes it does.

  104. Nigel Depledge

    @ Mementum (110) –
    I don’t quite understand this.

    If the OPERA team were measuring the speed of the neutrinos relative to the Earth’s surface, why does the satellite timing signal need to be compensated for the motion of the neutrinos?

    Does the experiment need to have accurate time relative to the source and detector, or relative to the neutrinos themselves? I would have thought (in my rather shaky layman’s understanding of SR) that the relativistic effects would mean that time is “perceived” completely differently by the neutrinos compared with the Earth’s surface. Is it, or not really?

  105. Mementum

    It needs to compensate because time is being measured using a “moving clock” (the GPS satellite)

    Because what they measure is time and then calculate the speed from the “known” (again using GPS) distance.

    In this experiment, the neutrino is one observer (travelling at almost “c”) and the GPS satellite (moving approx at 3900 m/s) is another observer. It is the classical SR time dilation example.

    If the neutrino could actually say how long it took to cover the distance it would probably say: t0 = 732km/”almost c” (because we think it can’t travel faster than c, but we really don’t know what the neutrino says)

    But the GPS satellite (moving relative to the neutrino) who has provided the timetags to the source and detector, says: hold on … your clock is ticking slower than my local clock (SR) … and therefore it took you … t1= 732km/”slightly above c”

    Because the only actual clock we have is that of the GPS satellite and both “observers” are moving relative to each other we proceed to calculate the time dilation seen by the GPS satellite during the flight of the neutrinos.

    At’ = At/squareroot( 1 – v2/c2)

    Where At = 2L/c and v is the speed of the satellite. And as Van Elburg calculated this will be in the 64ns range. Surprisingly Opera is telling us that the neutrinos seem to arrive 60ns too early (don’t forget there is an error margin)

    The experiment needs to have accurate timing and the GPS common view configuration is very accurate, but you don’t need to forget that the satellite is “moving” and is moving at a nice speed (even if far away from c) and this forces to take into account the effect.

    The neutrinos unfortunately don’t have a clock, so they can’t tell either how long the trip took or how slow the GPS satellite was ticking from their point of view.

    The experiment has nothing to do with the surface of the earth itself. The neutrino producer and detector could be located in deep space and the same calculations would apply (plus maybe 1 nanosecond here or there to account for the lack of gravity and no rotation of the start and end points)

    The surface of the earth is no reference. The neutrino passing through point A (actually being produce) at ‘tstart’ and the neutrino passing through point B (actually being detected because of a collision) at ‘tend’ are the only important things from the point of view of the other moving observer: the GPS satellite.

    Ideally, the experiment would need 2 perfectly synchronized (and static) clocks on both ends, but instead it has a single moving clock (a GPS satellite) offering time events to both ends.

    This synchronization would be no problem if we were measuring things that are not travelling at almost “c”, but unfortunately neutrinos do.

    And Neutrinos (even if travelling at almost c) don’t perceive time differently. What they perceive is that is different for all other things not travelling at almost c. This is the SR thing: the laws of physics are valid in all inertial frames of reference … we always see things the way we are expecting them to see in our frame of reference, no matter if our speed is altering things. External observers will see the effect. The GPS satellite is the one perceiving that the neutrino clock is running slower.

    Sidenote, the fact that GPS clocks (on board) are adjusted to produce timing that accounts for SR and GR makes them perfect for the experiment, because they produce the timing we are expecting with regards to any point on earth (height of the point has to be compensated at the point).

  106. Dav

    Nigel,

    As this discussion continues I am finding less and less to disagree with you on. Much of what you have said in this last post I agree with, though I might state it a bit differently. But, conceptually we are mostly on the same track.

    Regarding Mendel, he probably wasn’t the best choice because you are correct, he was a hellish plugger as well. Where I considered him intuitive was his arriving at his genetics/inheritence theories while contravening everyone elses. The fact that they needed the likes of the electron microscope, many decades and Watson & Crick to provide the molecular basis for his conclusions about genetics, qualified him in my mind. Envisioning genes without karyotyping or electron microscopes strikes me as very intuitive.

    However, I can’t really remember how he worded his specific descriptions of genes and alleles so I will kick him out for the time being and replace him with Da Vinci (I know, that was a bit too easy but he is the prototypical flash-of-intuition thinker).

    I would like to visit the Mendel museum and will try to do so if I get to that part of Europe sometime in the future. I don’t recall anything about the language barrier issue on his publications you mentioned. I remembered it as him being too obscure and not being seen as a professional scientist that was the cause of his theories being ignored. I will refresh my memory by looking online.

    I have to say that a lot of this really is subjective and heavily semantic in nature. Therefore, we can agree to disagree on what we mean by ‘flashes’ and ‘intuitive’ thinking. Simply stated, scientific intuition to me means prescient hypothesis not drawn directly or clearly elucidated from existing data and contravening the theories of the day. So, from that frame of reference I will stand by Einstein and Faraday(e.g. his hypothesis regarding magnetic lines of force extending into space around a conductor and non-ether field theory). Keppler’s hypotheses regarding planetary motion were ahead of eveyone’s (including Brahe) and they certainly went against the theories of the day. On the other hand, I cannot say how much of his intuition was a direct result of Brahe’s data or went well beyond it. Da Vinci, is not really arguable considering that he actually illustrated his flashes.

    Nigel said:
    “It is very rare for a major discovery in science to rest on a single moment of inspiration. More often than not, that flash of inspiration must be supported by reams and reams of data. Wegener is a good example here : he was kind-of right (although his proposed mechanism was wrong) but he did not have enough data to support his ideas so he was – metaphorically – shot down in flames.”

    We easily agree here. Figuring out the frequency of major discoveries by intuition and again by plugging along would likely be doable (though I would bet that it would take some effort and the data would be rather coarse at best). Statistically, I find it very likely that your point would be supported.

    Ah, entanglement, I would disagree and say that it is quite relevant, but would agree that it is somewhat immaterial (at this point). Nonetheless, it is quite likely to remain my all-time favorite hypothesis and subsequent profound validation (unless the FTL neutrinos are confirmed). I can understand your not wanting to get into it much here simply because there is still a great deal not known. If I was forced to have to speculate on what is behind entanglement (and possibly the FTL neutrinos), my answer might surprise you.

    For quite a long time I have suspected the existence of dimensions outside of our direct observation and/or experience. In fact, that concept was part of one of my indirect hypotheses resulting from much of my personal research over the years. I think there is evidence of extra-dimensionality all around us but our brain structure and epistemology likely interferes with our ability to recognize it, visualize it and/or explain it easily.
    I think there is evidence of extra-dimensionality from field theory, magnetics, gravity, quantum fluctuations and several other phenomena. Unfortunately, I am neither talented enough nor equipped well enough to do the plugging away necessary to adequately support extra-dimensionality. The best I can do is present my observations and conclusions during an informal ‘BS’ session and meetings with associates.

    This is an area where I have had many long, interesting and sometimes very animated, discussions with colleagues. I won’t bore you with the details here other than to say IF the neutrinos turn out to have arrived FTL, I will not be at all surprised if Einstein remains standing. I say this because I will also not be surprised to learn that the neutrinos did this by spending some of their time outside of our known “universe” (meaning our four dimensional one). It’s one of the possible reasons that might be responsible for neutrinos being only weakly interactive.

    Regarding research for things FTL, I would say that I would focus on the extra-dimensionality hypothesis. That is partly because it does not contravene those Einsteinian principles that you have been so dilligently championing and partly because I think practical experiments could be devised to test it.

    Extra-terrestrial life…let me go out on a limb here and say that intuitively, I cannot conceive of our universe without it. I don’t say that it is necessarily intelligent but, from what I know of the bacteria that inhabit undersea black smokers, the polar ice caps and other miscellaneous bits and pieces of information, I find an empty universe to be very unlikely. By the way, I do not claim in ANY way that this is a currently supportable conclusion. I agree that we have no credible evidence of extra-terrestrial life but, the way I see it, we do have some statistical probabilties.

    Regarding my ‘suspicion’ that the speed of light can be broken, I would say that I suspect it can be circumvented. Again, that is not based on scientific fact. So, for me accepting the probability of extra-terrestrial life and some form of net FTL travel are as close as I get to a “belief” system. Of course, I realize that I may be wrong on either or both counts. I can live with that.

    Fair enough on the ‘naysayer’ title. It was not meant to reflect negatively on you but rather to describe your philosophy on here, from my perspective. Sceptic is fine by me. Please understand that I have dealt with some sceptics that were so cynical and dissmissive that a couple of them have been proved wrong several times in my lifetime. Therefore, I do try and rein in my self-confidence (arrogance?) that my background and education in hard science has given me. Not always successfully as you will see below.

    I find it quite interesting learning what other scientists think about various issues and directions in the sciences. I learn quite a bit just listening and reading. I won’t say that I have never been fooled thinking something was crackpot idea only to learn later that it actually resulted in establishing a new invention. However, I share the responsibility for that error with the alleged crackpot since he was unbelievably sloppy in his research. Nonetheless, I learned a lesson and now try to keep an open mind until I have heard all of the details. No more a priori dismissals of the proposal (that being said, things like perpetual motion and “free energy” rate very highly on my ‘file 13′ filter. They have about 30 seconds ONLY if it sounds like it would be a radically new or different angle and/or it might be terribly funny) .

    Finally, regarding GR and SR, I consider them the best descriptions we have of macroscopic behavior. And, of course, quantum physics for the sub-microscopic. Nonetheless, I do not consider either of them even close to being complete. The fact that we cannot even define gravity, dark energy/matter, the interspace between where relativity takes over from quantum physics, is clear evidence that they aren’t. We are very far from establishing and quantifying the fabric of reality. This is especially so considering how much our brain lies to us and manipulates sensory data so as to maintain some form of consistent perception, whether or not it is correct.

    I hope I haven’t left anything hanging. I need to head out for motorcycle maintenance. Thanks for being patient on this response and thanks again for the interesting discourse.

    Regards,
    D

  107. Dav

    Neil,

    Your response regarding Keppler is somewhat addressed by me above. If, in fact, the laws of planetary motion were obvious from Brahe’s work, then Keppler’s clarification of the data cannot be construed as intuitive. If that is the case then I need to hunt for a new flash thinker. However, I have not been able to find anything that said it was Brahe’s documentation alone, or even primarily, that resulted in Keppler’s laws of planetary motion. If you have a reference easily available, I would appreciate the URL. Thanks

    Regards,
    D

  108. Richard B

    A quick check appears to reveal only three reported measurements of neutrino speed: the 2007 MINOS collaboration; the observed early arrival of neutrinos from supernova 1987A (only after the fact explained away via creative postdiction as being the consequence of neutrinos escaping an exploding star more quickly than light); and the OPERA report presently under discussion. The central value in each instance is superluminal. It seems significant that under the aegis of orthodox theory these massive particles should in fact always run slower than light.

  109. cneily

    As for the latitude difference, the relativity corrections are completely deterministic and the satellite clocks are controlled to run at the rate they would if stationary on the equi-potential geoid, a time-varying correction since the satellite orbits decay away from circular after a while. So any difference in latitude is already accounted for. The special and general effects are comparable in magnitude and first order in the system operation (if not compensated). To establish a common time reference at different locations there are various other error sources, measurable (iono delay), or model-based (tropo delay), cables, altitude above geoid, etc., but I assume these have long since been wrung out.

  110. Nigel Depledge

    @ Mementum (112) –
    Er, thanks, I think.

    That is all making my brain hurt, and reminding me why I went into Biochemistry instead.

    I think I have at least worked out the source of my confusion.

    What I thought was happening was that the GPS signal was used to calibrate a clock that was then physically transferred from CERN to OPERA to give both start and end points a common time reference. So I was thinking that the only relevant observers were at CERN and OPERA (and hence stationary with respect to the Earth’s surface), because this is where they made the measurements. What had not occurred to me is what you seem to be saying, which is that the GPS satellite that provided the time reference was a more pertinent “observer” than the instrumentation at CERN and OPERA.

    Is it, or not really?

  111. Nigel Depledge

    @ Dav (113) –
    I think I am beginning to see the source of our initial disagreement.

    I was viewing your comment about inspirational thinkers and pluggers as an either / or dichotomy, and this may have been false.

    The best scientists, it seems, were both.

  112. Yes the neutrino-faster-than-light experiment will NOT stand. So “If nothing travels faster than light then Einstein’s theory is right!” Nice rhyme… most mediocre minds (i.e. just about everyone in today’s world of physics) would dance to the line. A dance of the non-thinking crowd!

    Reality is more complex — a COUNTER-EXAMPLE exists that PROVES that (though Einstein’s postulates are correct), Einstein’s claim of having derived the Lorentz transformations is wrong, yes a COUNTER-EXAMPLE — and at least one Nobel prize winner takes this realization seriously. See http://physicsnext.org/ for details, a very simple read, but majority be warned… facing physics reality regarding the foundations could disturb a mediocre mind and make you react emotionally…for example, Howard Georgi got very angry!

  113. Neutrino Particles and e=mc2

    I like this link http://library.thinkquest.org/27930/relativity.htm It made me think about the crux of this issue. “The formula shows the equivalence of mass and energy and illustrates the fact that an increase in mass (m) is accompanied by an increase in energy (E) by mc2. The formula also shows an increase in energy (E) results in an increase in mass (m) by E/c2. In other words, as an object accelerates by gaining energy, it gains mass. As the object approaches the speed of light, its mass approaches infinity. An infinite amount of energy is required to accelerate an object to the speed of light, so the speed of light acts as a speed limit for matter.” Aren’t the neutrinos created from a high speed collision? And aren’t they a by product of the energy that is generated by CERN plus the collision? So they are not truly gaining energy and or mass since they are being created at a constant speed close to 98%c. So for them to be going faster than c does not require one to assume they are being accelerated from a relative speed of zero to v + c.

    So the problem is really just the interpretation of relativistic mass being associated with a velocity not an acceleration. The only energy increase required to make these particles accelerate to 98%c +v could be explained by the collision.

  114. Tealamide

    lets say for example, light has no mass, beacuse of which it is not affected by the medium it is travelling in! So how about neutrinos. Well, I dont know if smart scientists have realized this or not but the thing is neutrinos has mass!! This affects it in the travelling medium! So if neutrinos is travelling in air then the speed might change depending on the flow of air or other particles in air! As per the neutrinos that arrived in the supernovae in the 80s well, it travelled in vaccum so in its absolute speed not being affected by other medium!

  115. Rob

    would anyone know now that something can travel faster than light would that solve the entanglement issue in quantum mechanics

  116. The Other Jim

    …and it was an equipment problem after all…

    UPDATE 16 March 2012
    ICARUS experiment at Gran Sasso laboratory reports new measurement of neutrino time of flight consistent with the speed of light

    http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html

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